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Shortcomings of a Psychiatric Bible

Patients and parents concerned about mental illness have every right to be confused. The head of the federal agency that finances mental health research has just declared that the most important diagnostic manual for psychiatric diseases lacks scientific validity and needs to be bolstered by a new classification system based on biology, not just psychiatric opinion. The hitch is that such a biology-based system will not be available for a decade or more.

Dr. Thomas Insel, director of the National Institute of Mental Health, posted his critique of the manual in a “Director’s Blog”on April 29 and expanded on his reasoning in a recent interview with The New York Times. He was critiquing a forthcoming revision of the American Psychiatric Association ’s Diagnostic and Statistical Manual of Mental Disorders, the first major reissue since 1994. Although there have been controversies over particular changes in diagnostic descriptions, he said, the new revision involves “mostly modest alterations” from its predecessor.

The psychiatric association’s diagnoses are mostly based on a professional consensus about what clusters of symptoms are associated with a disease, like depression, and not on any objective laboratory measure, like blood counts or other biological markers. The mental health institute says scientists have not produced the data needed to design a system based on biomarkers or cognitive measures. To fill the gap, the agency started a program two years ago to finance research in biology, genetics, neuroscience, cognitive science and other disciplines with the ultimate goal of helping scientists define disorders by their causes, rather than their symptoms.

The underlying problem is that research on mental disorders and treatment has stalled in the face of the incredible complexity of the brain. That is why major pharmaceutical companies have scaled back their programs to develop new psychiatric drugs; they cannot find new biological targets to shoot for. And that is why President Obama has started a long-term brain research initiative to develop new tools and techniques to study how billions of brain cells and neural circuits interact; the findings could lead to better ways to diagnose and treat psychiatric illnesses, though probably not for many years.

Meanwhile, the diagnostic manual remains the best tool to guide clinicians on how to diagnose disorders and treat patients. Consensus among mental health professionals will have to suffice until we can augment it with something better.